Peripheral nerve impairment is caused by diseases, therapies, and injuries resulting in over 50,000 surgical procedures in the U.S. each year. Peripheral nerve repair is presently possible for transected nerve gaps of up to 3 cm. However, no treatment options are available for over 87% of patients having transacted nerve gaps greater than 3 cm because rapid scar formation overcomes slow nerve outgrowth. Indeed, current surgical options limit repair of peripheral nerves to a maximum gap of 3 cm. Attempts to surpass this 3 cm boundary have been ineffective.
Current surgical procedures for peripheral nerve damage are inadequate. Autografts and allografts are currently used but the availability and section of grafts and immunosuppression to prevent graft rejection are problems associated with graft procedures. Additionally, various types of conduits have been used for peripheral nerve replacement, but typically lack chemical, biological, and morphological guidelines provided by grafts. Among the drawbacks associated with presently deployed grafts and conduits is the fact that the repair, as stated, is limited to gaps of up to 3 cm in length. The length limitation is likely due to a lack of chemical and/or electrical stimuli. Indeed, various data indicate that an electrical stimulation field promotes upregulation of chemical, molecular and genetic factors to accelerate nerve repair over a 24-48 hour period. Experimental results from newt and bovine cornea transections indicate electric field gradients across a nerve transection may increase the promotion and direction of neurite outgrowth observed by single electric field gradients.
Due to the present limitations in the art for treating and repairing peripheral nerve damage, new therapies, materials and devices are needed. More specifically, new materials and methods are desperately needed to treat patients suffering from peripheral nerve impairment or injury and having a 3 cm or greater nerve gap.